CENTRE FOR ENDOSCOPIC AND MICROSCOPIC SPINE AND BRAIN SURGERIES

The most common type of pituitary tumor is a microadenoma (tumor) that is less than one centimeter in size. These tumors form on the pituitary gland and are not as dangerous as larger tumors. DNA mutations can cause pituitary microadenomas to form when cells within the pituitary gland grow and divide uncontrollably. Experts aren’t completely certain what causes these genetic mutations. There is a small hereditary factor in a few cases of pituitary tumors, but for the most part, this is not the case.As such, patients with multiple endocrine neoplasia, type I (a hereditary condition commonly known as MEN I) are at increased risk for pituitary tumors and other cancers of the endocrine system.

Microadenomas of the pituitary gland cause the following symptoms

The vast majority of pituitary tumors are not cancerous and do not progress to cause symptoms. However, pituitary microadenomas are more likely to function, which means they can produce hormones.A pituitary microadenoma can result in a number of hormone imbalances, resulting in a diagnosis of the tumor. Here are some of these hormone imbalances and the symptoms they cause:

• High growth hormone levels – Usually causes swelling and joint pain, and may cause abnormal bone growth on the hands, feet, and face. 
• ACTH (steroid hormone) levels at high levels – Weight gain, swelling, hair growth, vision changes, and low sex drive are symptoms of Cushing’s disease.
• Prolactin (luteotropic hormone) levels are high – Men may suffer erectile dysfunction and breast growth while women suffer osteoporosis, decreased sex drive, and infertility.

Microadenoma of the pituitary – treatment

Based on whether or not the tumor is functional, as well as the hormone it produces, the most appropriate treatment for pituitary microadenomas is determined.A pituitary microadenoma may be treated with any of the following options, depending on the individual’s circumstances:

• Surgical procedures 
• Treatment with radiation
• Medication 

This condition is uncommon but usually presents with profound neurological signs and symptoms, and the prognosis is poor.

Epidemiology

As opposed to acute myelopathies 4,5, acute spinal cord ischemia syndrome represents only 5-8% of all strokes 7. The demographic of affected individuals will reflect the underlying cause, although generally, there are two peaks with different etiologies. The most common cause for the development of this condition in children is trauma or cardiac malformations 5. In adults, the most common cause is atherosclerosis, usually associated with other complications (e.g. thoracoabdominal aortic aneurysm, thromboembolism).

Clinical presentation

The majority of patients developed symptoms quickly, with maximal symptomatology reached within 12 hours for >50% of patients and within 72 hours for the vast majority of patients.

The initial symptoms include back pain (60-70%), loss of bladder control (60%) and bowel control (40%) 4,5. It may seem counter-intuitive, but the first symptom that is felt is usually sensory (60%) despite the anterior cord being most commonly involved 4,5.

However, a patient with a higher cord lesion will experience acute and severe neurological impairment with the inability to walk due to paraplegia and paraparesis, as well as quadriplegia or tetraplegia. Almost all patients have some sensory disturbance, and the majority of patients require urinary catheterization.

It is possible to classify neurological impairments into several distinct entities, although there is great variability in the nomenclature and description of these entities. There are two common patterns of spinal cord infarcts based on which spinal artery is involved, an approach that is perhaps simplistic, but most people would agree with.

Anterior spinal artery syndrome (most common)

• bilateral (due to single midline anterior spinal artery)
• paralysis below affected level (initially flaccid; later spastic)
• pain and temperature sensory loss
• relative sparing of proprioception and vibration (dorsal columns)
• incomplete
  • anterior horn syndrome
  • man-in-the-barrel syndrome if cervical

• Posterior spinal artery syndrome
  • usually unilateral (due to paired posterior spinal arteries) 
  • complete sensory loss at the level of injury
  • proprioception and vibration loss below level
  • minimal, typically transient, motor symptoms

There are a number of less common presentations, which vary widely in terminology, including : 

• central spinal cord infarct (often the result of severe hypotension)
• sulcal artery syndrome (resulting in a partial Brown-Sequard syndrome)
• complete transverse spinal cord infarction (aka transverse medullary infarction).

A total of 100 patients with tic douloureux were followed up following surgery in two series; in one, the extradural approach was used and the trigeminus sensory root was manipulated in its dural sleeve, while in the other, the trigeminus sensory root was manipulated in the dura. The intradural approach, which caused less postoperative sensory impairment in 100 patients, injured the semilunar ganglion less, and caused more complete relief in 62% of the cases. The patients, however, experienced mild recurrences in 11.5% and severe recurrences in 26.5% of the cases.

A degree of sensory loss had been reported in 26% of those with successful treatment, as well as in 28.3% of those with ineffective treatment. Neither surgical trauma to the nerve root nor incision of the nerve root’s dural sleeve was necessary to ensure success. Neurolysis or manipulation of the sensory root at the point where it crosses the apex of the pars petrosa of the temporal bone appeared to be the key part of the operation.

Many experts believe the cause of this condition is segmental demyelination of the trigeminal sensory nerve in the nerve root or brain stem, accompanied by chronic compression of the nerve root.

Multiple sclerosis is also a link. The incidence of multiple sclerosis is approximately 4 per 100,000 of the population, and only gets worse with age. The average age of onset is 60, with few diagnosed before age 40.

Clinical hygienists at chairside treating patients with TN need to understand more about this, as the triggers can have a profound impact on treatment. It has been described as an electric lightning bolt of intense pain to yawn, speak, chew, brush one’s teeth, and simply touch one’s face. Imagine the extraoral fulcrum you might use during instrumentation. Even the lightest feather-like finger rest could prove disastrous to TN patients. The painful sensation is usually unilateral, lasts several seconds to several minutes, and can occur a few times a day or hundreds of times a day.

Remission can occur, but the intervals between relapses tend to shorten as the patient ages. TN is diagnosed based only on history, after hearing the patient’s description of the pain. It is believed that the condition can lead to depression since daily life activities can be impaired. Experts find that symptoms worsen over time and become less responsive to medication, despite dosage increases and other agents being added.

When it comes to treatment success for TN, standard definitions vary depending on whether it is medical or surgical. If at least half of pain relief compared to baseline readings is achieved with medication, it is considered successful. However, with surgical studies, measurements are different. Complete pain relief is the goal, so this would be considered treatment success.